The present invention relates to a method and an apparatus for taking up the tape of magnetic tape recorder or the like.
In taking up tape at high speed, a small clearance is formed between the take-up reel and the tape. The surrounding air is enfolded in this space as the tape travels and the reel rotates, generating a floating force on the tape. Further, the tape is oscillated in its lateral direction due to irregularities such as vibrations of the various mechanical parts and variation in the tape tension due to eccentric rotation of the reels. The surface defined by the top edge of the wound tape, or the coil face is thus made irregular, resulting in the so-called irregular take-up phenomenon of the tape.
When the tape is wound irregularly, its appearance is poor, and undesirable magnetic traces are formed on the tape, resulting in frequent generation of reading or recording errors by the magnetic reading or recording head.
In order to solve these problems, it has been conventional practice to press the tape in the vicinity of the take-up part with a side roll so as to regulate the tape take-up, thereby eliminating the lateral irregularity of the tape. However, in this method, since the roller and the tape directly contact each other, the edge of the tape is disadvantageously damaged. Dropout may also occur due to the circulation and adhesion of dust. Still further, the benefit of known means of eliminating irregular take-up of the tape disappear at take-up speeds over 5-6 m/sec. Thus, high speed take-up has been impossible. Although it is possible to increase the tape speed limit, at which the winding irregularity begins, by increasing the tape tension, this is not desirable since it leads to separation and degradation of the magnetic layer of the magnetic tape.